It has an area of 2,247 square kilometres (868 sq mi) (including islands) with a surface elevation of 258 metres (846 ft).

It has a complex shoreline with many islands, long peninsulas and deep bays.

The community of South Indian Lake is located on the southeast shore, about 130 kilometres (81 mi) (by air) north of the city of Thompson.

PR 493, a gravel road, begins at Leaf Rapids on PR 391 (also a gravel road), running 219.1 kilometres (136.1 mi) northeast to its terminus at South Indian Lake.

[8] An artificial outflow channel (South Bay Diversion Channel) was also created from South Bay of Southern Indian Lake to Issett Lake.